1. Field of the Invention
The present invention relates to a method for producing a modified conjugated diene-based polymer, and a method for producing a vulcanized polymer.
2. Description of the Related Art
With the increased interest in environmental problems, requirements for fuel saving of automobiles have recently increased, and it has been requested for a rubber composition to be used in an automobile tire to be superior in fuel economy. A rubber composition containing a conjugated diene-based polymer such as polybutadiene or styrene-butadiene copolymer, and a reinforcing agent is used as a rubber composition for an automobile tire, and a conjugated diene-based polymer to be used as a rubber component has been studied so as to improve performances as a rubber composition for a tire.
For example, JP-A-1-217047 proposes a conjugated diene-based polymer in which a butadiene-styrene copolymer is modified with an acrylamide compound wherein a dialkylamino group is combined with a nitrogen atom of acrylamide via an alkylene group. JP-A-2005-344039 proposes a conjugated diene-based polymer in which a butadiene-styrene copolymer is modified with an isocyanurate compound wherein a trialkoxysilyl group is combined with a nitrogen atom of an isocyanurate group via an alkylene group.
However, a rubber composition containing the above modified conjugated diene-based polymer was still unsatisfactory in fuel economy.